It is known that the polymerization of chloroprene can be carried out in the presence of anionic active emulsifiers based on alkali metal salts of disproportionated abietic acid, and in the presence of condensation products from naphthalenesulphonic acid and formaldehyde.
In the conventional work-up by freezing out, some of the surface-active emulsifiers are removed from the polymer and reach the waste water. If the emulsifiers are not biologically degradable, expensive processes must be used to recondition the water.
The condensation products from naphthalenesulphonic acid and formaldehyde which are conventionally used as the second emulsifier, although avoiding a number of disadvantages which other emulsifiers display,
formation of insoluble polymers,
considerable formation of foam during the removal of the remaining monomer in the degassing,
inadequate or too strong polymer adhesion in the drying equipment,
deterioration of product properties such as reduction of the pot life in the case of raw material adhesives,
have, however, two serious disadvantages.
Firstly, these products are not biologically degradable, and secondly they cause a certain discoloration of the polymer during drying, its use as adhesive for pale materials thereby being made impossible.